Loud speaker



May 31, 1 932. ANDRES 1,861,105

LOUD SPEAKER Filed May 27, 1929 2 Sheets-Sheet 1 May 31, 1932. P. G.ANDRES I 1,861,105

LOUD SPEAKER Patented May 31, 1932 UNITED STATES PATENT OFFICE PAUL G.ANDRES, OF LA GRANGE, ILLINOIS, ASSIGNOR TO TEMPLE CORPORATION, OF

' CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE LOUD SPEAKER Applicationfiled. May 27, 1929. Serial N0. 366,421.

My invention relates to 'loud speakers, and has among its other objectsthe production of devices of the kind described that are eflicient,durable andsimple in construction.

A particular object of the invention is to provide improved means forbringing the reproducing unit or mechanism of a loud speaker intoadjusted positions with respect to the diaphragm.

Another particular object of the invention isto provide improved-meansfor operatively connecting the diaphragm of a loud speaker to thereproducing unit thereof.

The preferred form of the invention is embodied in a loud speakercomprising a plurality of tensioned diaphragms which have their centralportions operatively connected to a reproducingunit, the reproducingunit being provided with an armature disposed within a coilsubjected totelephonic currents. Improved adjustable means is provided forconnecting 'the'diaphragm to the armature and the reproducing unit ismounted on a bracket which may be brought into adjusted positions withrespect to the diaphragm to properly position the armature within thecoil.

Many other objects and advantages will become apparent as thisdescription progresses, reference being had to the accompanyingdrawings, wherein:

Figure 1 is a rear elevation of a loud speaker embodying the invention;

Fig. 2 is a section taken on line 2-2 of Fig. 1;

Fig. 3 is a section taken on line 33 of Fig. 1;

Fig. 4 is a Fig. 1;

Fig. 5 is a section taken on the line 55 of Fig. 1, and

Fig. 6 is a section taken on line 66 of Fig. 4.

In the drawings, I have illustrated my invention as embodied in a loudspeaker comprising a plurality of diaphragms, but it is to be understoodthat my invention is limited to this construction only to the extentindicated in the appended claim.

The loud speaker illustrated in the drawsection taken on line 44 of ingspreferably comprises a rectangular frame 10 provided with a pair ofspaced cross-bars 11 to which a pair of spaced vertical bars 12 arerigidly secured. The diaphragm 14 is preferably formed from fabric,

or the equivalent, and has its marginal portions rigidly secured to theframe 10 and a smaller diaphragm 15 of like material has its marginalportions secured to the cross-bars 11 and the vertical bars 12. It willbe noted that the diaphragms 14and 15 are tensioned along divergentlines and that they are somewhat conical in shape to provide apiceswhich are aperture'd to receive a sleeve or bushing 17 (see Fig. 5). Theapertured portions or apices of the diaphragms 14 and 15 are preferablyre-enforced by washers 19 and and 20, respectively, preferably formedfrom fabric. diaphragms' are clamped to each other hetweenmetallicwashers 21 and 22 positioned upon the sleeve or bushing 17, the sleeveor bushing 17 being provided with an outwardly extending flange 23 and anut 24 for this purose.

One end of the sleeve or bushing 17 is preferably slottedlongitudinally, and is preferably screw-threaded, as at 25, to receive anut 26 having an extension 27. The extension 27 has a conical innersurface engageable, with a similar surface provided upon the slotted endof the sleeve orbushing 17. The construction is such that the nut 26 maybe manipulated to clamp the slotted end of the sleeve or bushing 17against a rod 30 to rigidly secure the rod to the sleeve. One end of therod 30 is rigidly secured to a relatively flexible and resilient arm32'which has one of In this instance, the apices of the its ends rigidlysecured to a bracket member 1 33 by a screw 34, the other end of the arm32 being secured to one end of a pin 35 which has itsother end securedto an armature 36 forming part of a reproducing unit indicated generallyby reference character 87. It will As best shown in Figs. 1, 2 and 3,the bracket member 33 comprises a central disc portion 40 havingintegral arms 41, 42 and 43, the arms 42and 43 being secured to one ofthe bars 12 and one of the bars 11, respectively, by screws 45, or theequivalent. At its outer end, the arm 41 is provided with an aperture 48to accommodate a rod 50 which has one of its ends rigidly secured to acupshaped member 51 fastened to the uppermost bar 11. It will be notedthat the cup-shaped member 51 is seated in a recess 53 formed in the bar11 and that a compression spring 54 is disposed around the rod 50 and isinterposed between the cup-shaped member 51 and the arm 48. Thecompression spring 54 tends to displace the bracket member 33 in adirection away from the diaphragms 14 and 15, but such displacement islimited by a knurled nut 56 screw-threaded upon the rod 50.

Secured to the bracket member 33 is a permanent magnet 60, the legs ofthe magnet being apertured to receive bolts 61 and 62 which co-operatewith nuts 63 and 64, respectively, to rigidl secure I the magnet inplace upon the brac et 33. The magnet is preferably Erovided with polepieces 65 and 66 having -shaped ends which terminate adjacent the endsof the armature 36 (see Fig. 4). Disposed Within the U-shaped ends ofthe pole pieces 65 and 66 is winding 68 carried by a sleeve 7 O which isformed from non-magnetic material. The armature 36 is resilientlymounted within the sleeve 70 by any suitable means, such as, forinstance, a relatlvely thin piece of sheet metal 7 2. As is well knownto those skilled in the art when the winding 68 is subjected totelephonic currents, the armature 36 vibrates and this vibration istransagainst the action of the spring 54 or in the direction of theaction of the spring 54 to properly position the winding 68 and sleeve70 with respect to the armature 36 so that when the armature 36 is notenergized, it will occupy a predetermined position within thesleeve.

While I have shown and described certain embodiments of my invention, itis to be understood that it is capable of many modifications. Changes,therefore, in the construction and arrangement may be made withoutdeparting from the spirit and scope of the invention as disclosed in theappended claim,

in which it is my intention to claim all novelty inherent in myinvention as broadly as possible, in view of the prior art.

What I claim as new is:

A sound reproducing device comprising a frame, a diaphragm extendingacross said frame, a second frame mounted on the first mentioned frame,a second dia hra gm mounted on said second frame, a bracket having oneof its ends secured to said second frame, a bolt secured to said secondframe and extending through the other end of said bracket, a springurging said bracket in one direction, a nut screw-threaded on said boltand adapted to displace said bracket against the action of said spring,a sound reproducing unit mounted on said bracket intermediate its ends,said sound reproducing unit having an armature and means including aflexible member for operatively connecting said armature to saiddiaphragms.

In testimony whereof, I have hereunto set my hand this 17th day of Ma1929.

- PAUL ANDRES.

mitted to the diaphragms 14 and 15 which translate them into sound.

The means for operatively connecting the windin 68 to a source oftelephonic current, prefera 1y comprises conductors and? 6 connected tothe terminals of the winding. The outer ends of the conductors 75 and 76 are connected to terminals 78 and 79, respectively, carried by a bar80 formed of electrical insulation. The bar 80 is apertured to receive abolt 82 screw-threaded through the bracket member 33 and nuts 83screw-threaded upon the bolt secure the bar 80 thereto. Suitableconductors, as indicated at 87 and 88, may be provided to connect withthe ter- 55 minals 78 and 79 to the output circuit of a radio-receivingset, or the equivalent.

Obviously, the nut 26 may be manipulated to clamp the slotted end of thesleeve 17 in any desired position upon the rod 30 so that 60 thediaphragms 14 and 15 will be correctly positioned with respect to thearm 32 and there will be no tendency to distort the sound wavespropagated by the diaphragm. It is also apparent that the nut 56 may bemanipu-

